Additional sanity checking for binding keys in `\data\model\Relationship`.
Additional sanity checking for binding keys in `\data\model\Relationship`.

wbeater/lithium,pixelcog/lithium,graphis/lithium,jails/lithium,mehlah/lithium,graphis/lithium,muyehub/lithium,davidpersson/lithium,SensCritique/lithium,whowgames/lithium,qoqa/lithium,m4rcsch/lithium-core-library,SensCritique/lithium,muyehub/lithium,mehlah/lithium,datachand/lithium,UnionOfRAD/lithium,qoqa/lithium,UnionOfRAD/lithium,datachand/lithium,jails/lithium,m4rcsch/lithium-core-library,pixelcog/lithium,whowgames/lithium,wbeater/lithium,davidpersson/lithium